I will be going on a long trip (1600 miles) and would like to know how the 80 handles out on the highway in terms of speed and stability. I have never really taken my 80 up to speed since it stays in locally and i never really get it over 55 or so. I will also be doing some highspeed drving 65-85 MPH. Since I will be doing hway driving, is it ok to jump the psi in the tires to about 35-40psi?? I could maybe get a little more mpg?? Will travelling that fast cause any accereated wear on the 4wd system or any other components. Car has 145k miles and i just changed the plugs and filters and will do the oil tomorrow. Input would be great